package com.net.common.encryption;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;
import javax.crypto.spec.IvParameterSpec;
import java.util.Base64;

/**
 * @author hjh
 */
public class DesUtils {

    private final static Logger logger = LoggerFactory.getLogger(DesUtils.class);
    /**
     * 偏移变量，固定占8位字节
     */
    private final static String IV_PARAMETER = "12345678";
    /**
     * 密钥算法
     */
    private static final String ALGORITHM = "DES";
    /**
     * 加密/解密算法-工作模式-填充模式
     */
    private static final String CIPHER_ALGORITHM = "DES/CBC/PKCS5Padding";
    /**
     * 默认编码
     */
    private static final String CHARSET = "utf-8";
    /**
     * 设置秘钥key
     */
    private static final String KEY_STR = "net-2022";
    /**
     * 加密器
     */
    private static Cipher sEncryptCipher;
    /**
     * 解密器
     */
    private static Cipher sDecryptCipher;

    static {
        try {
            DESKeySpec dks = new DESKeySpec(KEY_STR.getBytes(CHARSET));
            SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(ALGORITHM);
            SecretKey secretKey = keyFactory.generateSecret(dks);

            IvParameterSpec iv = new IvParameterSpec(IV_PARAMETER.getBytes(CHARSET));

            sEncryptCipher = Cipher.getInstance(CIPHER_ALGORITHM);
            sEncryptCipher.init(Cipher.ENCRYPT_MODE, secretKey, iv);

            sDecryptCipher = Cipher.getInstance(CIPHER_ALGORITHM);
            sDecryptCipher.init(Cipher.DECRYPT_MODE, secretKey, iv);
        } catch (Exception e) {
            logger.error("生产des密钥失败", e);
        }
    }


    /**
     * DES加密字符串
     *
     * @param data 待加密字符串
     * @return 加密后内容
     */
    public static String encrypt(String data) {
        try {
            byte[] bytes = sEncryptCipher.doFinal(data.getBytes(CHARSET));
            return new String(Base64.getEncoder().encode(bytes));
        } catch (Exception e) {
            return data;
        }
    }

    /**
     * DES解密字符串
     *
     * @param data 待解密字符串
     * @return 解密后内容
     */
    public static String decrypt(String data) {
        try {
            return new String(sDecryptCipher.doFinal(Base64.getDecoder().decode(data.getBytes(CHARSET))), CHARSET);
        } catch (Exception e) {
            return data;
        }
    }

    public static void main(String[] args) {
        System.out.println(encrypt("userid"));

    }
}
